Molteno Formation

Molteno Fm

Period:

Triassic

Age Interval:

Late Triassic (Carnian – Norian)

Province:
SouthAfrica-Namibia-Botswana

Type Locality and Naming

Main Karoo Basin (SE), Main Karoo Basin (Eastern/Northern Forebulge), South Africa. Lowest formation in Stormberg Gr

Synonym: Basal Stormberg Gr

Lithology and Thickness

Coarse siliciclastics, specifically sandstone and conglomerate

Lithology Pattern:

Sandstone

Relationships and Distribution

Lower contact

Separated from the underlying Burgersdorp Fm (Beaufort Group) by a major stratigraphic hiatus spanning the Middle Triassic (Ladinian) (Figure 2).

Upper contact

Overlain by the fluvial sandstones and mudstones of the Elliot Fm

Regional extent

Main Karoo Basin (Figure 2; Figure 5).

GeoJSON

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Fossils

Age

Late Triassic (Carnian to Norian). The text explicitly cites Anderson and Anderson (1983) to distinguish its Late Triassic age from the Middle Triassic (Anisian) age of the Manda Beds in Tanzania (Section 2.2.1).

Age Span:

Beginning stage:

Carnian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

237.00

Ending stage:

Norian

Fraction up in the ending stage:

0.4

Ending date (Ma):

218.68

Depositional setting

Fluvial environments (typically braided stream) deposited during the "overfilled" phase of the Karoo retroarc foreland system (Figure 2).

Depositional pattern:

Additional Information

The Molteno Formation acts as the basal unit of the Stormberg Gr in the type-basin, reflecting a renewed pulse of coarse clastic input following a significant period of erosion or non-deposition during the Ladinian (Figure 2).

Compiler:

From the O. Catuneanu et al. / Journal of African Earth Sciences 43 (2005) 211–253